Why is it doing this?

[Pretorien]

My 2014 Macbook Pro/El Capitan is operating normally with one exception - Safari - which until recently behaved like all my other programs - opened in full screen with the menu bar at the bottom and a row of functions - open,close, minimize, time, charge etc at the top. I don't recall changing anything but now it opens in a rectangle at lower left and, if I maximize it, the menu bar and functions disappear! I can get back to the functions by moving the mouse pointer to the top but the menu bar won't return.

What has changed? How do I get back to "normal?"

Thanks

 

[Pretorien]

Fixed it - Under the "Window" heading, clicked on "Zoom" - now seems to be back to normal (I don't know how it went astray)